The reason it was added was because prior to v9, farms would just autogenerate an animal every X ticks - forever. Eventually, if you weren't using your animals, your farms would have spawned thousands of entities which really lag the game. So, to combat that, if the animals aren't being used they will starve. If your wheat is all being used, it helps the player see they have too many farms

I'm not sure what I am doing wrong..I just started playing at v8 and had finally started to find my way in the game. I have nearly a 100 wheat laying on the ground next to my farm animals and let my townies idle for a half hour. Not once did they feed any of the animals and they are all just starving off. I only have 6 farms (2 each chicken, cow, pig) but my 'corral' is just a bone yard. I have fewer living animals than I do farms. Am I missing something obvious? I don't see any way of keeping enough animals alive to have meat be a productive part of my townies food supply.